In consideration of the uncertainty of basic events failure rate and lack of probability statistical information in fault tree analysis( FTA) of excavator variable-frequency speed control system, the interval theory w...In consideration of the uncertainty of basic events failure rate and lack of probability statistical information in fault tree analysis( FTA) of excavator variable-frequency speed control system, the interval theory was employed and combined with conventional FTA method. The basic events failure probabilities were described by interval numbers,and the interval operators of logical gates in FTA were deduced based on interval theory. Finally,the reliability assessment of excavator variable-frequency speed control system was done by interval FTA method. The result shows that the interval FTA method is suitable for the complex system with insufficient failure data.展开更多
CNC machine tool is a large complex system which contains both mechanical and electrical components.As one of these components,the spindle is crucial for the performance of CNC machine tool.To improve the quality of C...CNC machine tool is a large complex system which contains both mechanical and electrical components.As one of these components,the spindle is crucial for the performance of CNC machine tool.To improve the quality of CNC machine,the reliability of spindle was evaluated in this paper using a fault tree analysis(FTA)method.The FTA method is a set of calculation methods based on Boolean algebra.However,it is difficult to analyze a large and complex fault tree with inaccurate results and low efficiency as well as the complexity of time and space.Both of them will result in the so-called "combinatorial explosion".To overcome this problem,the analysis method based on binary decision diagram(BDD)was introduced in our works,and a sorting method about bottom events was also recommended which can reduce the size of the BDD effectively.展开更多
为进一步提高大型游乐设施使用安全性,以大型游乐设施事故为研究对象,提出了融合故障树分析法(Fault Tree Analysis,FTA)、层次分析法(Analytic Hierarchy Process,AHP)和逼近理想解决策方法(Technique for Order Preference by Similar...为进一步提高大型游乐设施使用安全性,以大型游乐设施事故为研究对象,提出了融合故障树分析法(Fault Tree Analysis,FTA)、层次分析法(Analytic Hierarchy Process,AHP)和逼近理想解决策方法(Technique for Order Preference by Similari-ty to Ideal Solution,TOPSIS)的事故预防方案决策分析。定性定量地分析了大型游乐设施事故危险因素的影响程度,量化了事故预防措施方案以及决策过程。结果表明,在摩天轮坠落事故中,基本事件X3维修保养不到位和X4检查不到位对事故发生的影响程度最高,二者均属于安全制度因素。急需优先采取的事故预防方案为方案6,包括避免乘客和操作人员不安全行为,应对室外不利环境,完善安全制度和提高应急救援能力等措施。展开更多
为了分析机场跑道侵入的影响因素,更有针对性地对预防机场跑道侵入提出合理建议,结合相关信息通告中统计的数据,首先从人员因素、环境因素、设备因素和管理因素4个方面分析跑道侵入的事故成因,并建立了故障树(Fault Tree Analysis,FTA)...为了分析机场跑道侵入的影响因素,更有针对性地对预防机场跑道侵入提出合理建议,结合相关信息通告中统计的数据,首先从人员因素、环境因素、设备因素和管理因素4个方面分析跑道侵入的事故成因,并建立了故障树(Fault Tree Analysis,FTA)模型和贝叶斯网络(Bayesian Network,BN)模型,然后利用软件Netica对贝叶斯网络模型进行了后验概率推理与敏感性分析,最后根据分析结果提出了相应的建议。结果表明,人员因素影响程度最大,其次是管理因素,而环境因素和设备因素的影响程度相对偏小。展开更多
Smart grid was proposed as a practical form of future power distribution system. Evaluating the reliability of smart grids was of great importance and significance. A revised fault tree model was proposed to distingui...Smart grid was proposed as a practical form of future power distribution system. Evaluating the reliability of smart grids was of great importance and significance. A revised fault tree model was proposed to distinguish and separate grid-connected operation mode and islanded operation mode of smart grids,focusing on the perspective of the consumers. A hierarchical Monte Carlo simulation method for reliability evaluation was also proposed based on the proposed fault tree model. A case of reliability evaluation for the future renewable electric energy delivery and management( FREEDM) system was carried out and analyzed. The proposed methods can be applicable to other forms of smart grids.展开更多
基金National High-Tech Research and Development Program(863 Program),China(No.2012AA062001)
文摘In consideration of the uncertainty of basic events failure rate and lack of probability statistical information in fault tree analysis( FTA) of excavator variable-frequency speed control system, the interval theory was employed and combined with conventional FTA method. The basic events failure probabilities were described by interval numbers,and the interval operators of logical gates in FTA were deduced based on interval theory. Finally,the reliability assessment of excavator variable-frequency speed control system was done by interval FTA method. The result shows that the interval FTA method is suitable for the complex system with insufficient failure data.
基金National Science and Technology Major Project of China(No.2013ZX04013-011)
文摘CNC machine tool is a large complex system which contains both mechanical and electrical components.As one of these components,the spindle is crucial for the performance of CNC machine tool.To improve the quality of CNC machine,the reliability of spindle was evaluated in this paper using a fault tree analysis(FTA)method.The FTA method is a set of calculation methods based on Boolean algebra.However,it is difficult to analyze a large and complex fault tree with inaccurate results and low efficiency as well as the complexity of time and space.Both of them will result in the so-called "combinatorial explosion".To overcome this problem,the analysis method based on binary decision diagram(BDD)was introduced in our works,and a sorting method about bottom events was also recommended which can reduce the size of the BDD effectively.
文摘为进一步提高大型游乐设施使用安全性,以大型游乐设施事故为研究对象,提出了融合故障树分析法(Fault Tree Analysis,FTA)、层次分析法(Analytic Hierarchy Process,AHP)和逼近理想解决策方法(Technique for Order Preference by Similari-ty to Ideal Solution,TOPSIS)的事故预防方案决策分析。定性定量地分析了大型游乐设施事故危险因素的影响程度,量化了事故预防措施方案以及决策过程。结果表明,在摩天轮坠落事故中,基本事件X3维修保养不到位和X4检查不到位对事故发生的影响程度最高,二者均属于安全制度因素。急需优先采取的事故预防方案为方案6,包括避免乘客和操作人员不安全行为,应对室外不利环境,完善安全制度和提高应急救援能力等措施。
文摘为了分析机场跑道侵入的影响因素,更有针对性地对预防机场跑道侵入提出合理建议,结合相关信息通告中统计的数据,首先从人员因素、环境因素、设备因素和管理因素4个方面分析跑道侵入的事故成因,并建立了故障树(Fault Tree Analysis,FTA)模型和贝叶斯网络(Bayesian Network,BN)模型,然后利用软件Netica对贝叶斯网络模型进行了后验概率推理与敏感性分析,最后根据分析结果提出了相应的建议。结果表明,人员因素影响程度最大,其次是管理因素,而环境因素和设备因素的影响程度相对偏小。
文摘Smart grid was proposed as a practical form of future power distribution system. Evaluating the reliability of smart grids was of great importance and significance. A revised fault tree model was proposed to distinguish and separate grid-connected operation mode and islanded operation mode of smart grids,focusing on the perspective of the consumers. A hierarchical Monte Carlo simulation method for reliability evaluation was also proposed based on the proposed fault tree model. A case of reliability evaluation for the future renewable electric energy delivery and management( FREEDM) system was carried out and analyzed. The proposed methods can be applicable to other forms of smart grids.
